Intraocular lens including silicone oil

ABSTRACT

An intraocular lens (IOL) having an optical axis extending in an anterior-posterior direction and an equator extending in a plane substantially perpendicular to the optical axis is described. The IOL includes: an elastic anterior face located anterior to the equator; a posterior face located posterior to the equator, wherein the anterior face, the posterior face, or both comprises a poly(dimethylsiloxane) elastomer having a durometer between about 20 Shore A to about 50 Shore A; and a chamber located between the anterior face and the posterior face comprising a silicone oil comprising polysiloxanes comprising diphenyl siloxane and dimethyl siloxane units, the silicone oil having a maximum viscosity of about 800 cSt at 25° C.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationNo. 63/053,134, filed on Jul. 17, 2020, which is incorporated herein inits entirety.

TECHNICAL FIELD

The present disclosure relates to an accommodative intraocular lens thatincludes a chamber comprising a silicone oil comprising polysiloxanescomprising diphenyl siloxane and dimethyl siloxane units that improvethe response time of the intraocular lens.

BACKGROUND

The human crystalline lens can be affected by one or more disorders orconditions that reduces its function and/or reduces the clarity of thelens. A common condition that occurs with aging is the gradualopacification and reduced transparency of the lens of the eye. Thiscondition is termed a cataract. Surgical removal of a cataractous lensand placement of an artificial replacement lens (such as an intraocularlens (“IOL”)) within the eye is a common surgical procedure. Thedevelopment of a suitable IOL that can provide the optical quality andaccommodation provided by the youthful biological lens has not beendeveloped.

There are generally two classes of IOLs that have been developed thatattempt to overcome the lack of accommodation of an IOL used to replacethe natural lens when cataract surgery is performed:pseudo-accommodating lenses and accommodating lenses. Apseudoaccommodating lens can be a multiple focal point lens that uses aring for distance focus and one or more center optics for intermediateand near focus. Other designs use diffraction optics to obtain a rangeof focus or use optics to achieve an extended depth of focus (EDOF).Multi-focus optics, diffraction optics, and EDOF optic IOLs can resultin disruptive optical aberrations such as glare, halos, reduced contrastsensitivity, etc. Centration of these lenses within the capsular bag isimportant to their best visual function. These lenses use non-deformingoptical elements and do not achieve the visual quality of a natural,youthful lens of the human eye. The accommodating class of IOLs includesa silicone elastomeric hinged lens that allows forward movement of theoptic when the eye focuses at near. These lenses are typically placed inthe lens capsular bag (the remaining thin layer of basement membranethat is the outermost layer of the natural lens and is typically left inplace when the contents of the lens are removed during cataractsurgery). Due to progressive fibrosis and stiffening of the lens capsulefollowing cataract removal, the effective accommodation with theselenses is known to diminish over time. Overall, these lenses may beadequate for distance and intermediate vision, but only provideaccommodation of about two diopters at most and this value has beenshown to diminish over time.

Shaped haptics, levers, or other mechanical elements have been describedto translate the axial compressive force along the optical axis exertedby the elasticity of the lens capsule and/or the radial compressiveforce exerted by the ciliary muscles to affect a desired axialdisplacement of the IOL optic. Additional examples may also provideflexible hinge regions of the haptic to facilitate axial displacement ofan IOL. Several examples include annular ring elements in contact withthe lens capsule and that use the axial compression of applied force bythe capsule along the optical axis to affect axial displacement of theIOL optic. However, these IOLs are configured to be generally of fixedoptical power and in line with the optical axis of the eye. As such, theaxial displacement of the optical elements of these IOLs that ispossible limits the dioptric power change attained. Some single ormultiple optic lenses have incorporated a shape changing and axialdisplacement changing combination of lenses, such as a shape changingoptic coupled to zonular contact haptics whereby axial compression ofthe lens capsule along the optical axis during accommodation results inboth anterior displacement of the flexible optic, as well as compressionof the sides of the optic. Other described IOLs rely on a posteriorflexible region separated from a flexible anterior lens by anarticulating member about the circumference.

Surface shape changing lenses are more likely to result in greaterdegrees of dioptric power change. These lenses include lenses with fluidfilled chambers that rely on axial compression along the optical axis bythe lens capsule to force fluid from one chamber into a central lens andthereby change the shape and therefore the optical surface power of thelens. Other lenses use the compressive force by the lens capsule toprovide a radial compressive force about the equatorial periphery of aflexible lens to shape change the lens. These are generally two-partsystems with a circumferential haptic design with a central fixedposterior lens that fits within the capsule and then a separately placedpliable optic secured within the outer haptic ring. Compression by the“elastic” lens capsule is meant to provide an axial compressive forcealong the optical axis to the central lens flexible optic. Other IOLsuse a compressive force exerted on rigid haptics to compress a pliableoptic against a separate fixed power posterior lens. These IOLs rely onthe shape change of the posterior surface of the pliable optical elementpressed against a fixed optical element or pressed against a relativelyrigid posterior lens capsule to alter the dioptric power of the lenssystem. Other IOLs incorporate a skirt with a capsular contact ring.Such IOLs rely on compression exerted by the “elastic” lens capsule toimpart a compressive force on a capsular contact ring and the mechanicaldesign of this ring pulls radially about the equator of the IOL'sflexible optic. Again, because these IOLs rely on retained capsularelasticity/pliability and because it is generally known that the lenscapsule following cataract surgery becomes less pliable and morefibrotic, it is unlikely these lenses will retainaccommodating/dis-accommodating ability. None of the shape changingaccommodating IOLs described above mimic the natural human lens duringaccommodation or effectively account for the inevitable loss of capsularelasticity/pliability and progressive fibrosis and stiffening of thelens capsule.

Intraocular lenses (“IOL”) may comprise a bulk polymeric material withone or more fluids disposed therein. For example, some accommodatingIOLs use fluid movement within the IOL, or a change in fluid pressurewithin the IOL, to effect optical power change in the IOL. Silicone oilis an example of a fluid that can be used in an IOL. When fluids, suchas silicone oil are used in an accommodating intraocular lens, thefluid, over time, may tend to swell into the bulk material. This canalter the physical properties of the bulk material. It is thereforedesirable to minimize the amount of swelling into the bulk material. Itmay also be important to provide silicone oil that does not reduce theresponse time of the accommodating IOL.

Accommodating IOLs can utilize the eye's natural ciliary musclemovements to provide accommodation in the IOL. For example, someaccommodating IOLs are implanted within a patient's capsular bag (afterthe native lens contents have been removed) and respond radial forcesapplied to the lens capsule by the ciliary muscle via the zonules tochange the power of the IOL. Some IOLs are designed to be implantedoutside of the lens capsule and accommodate in other ways. Whatever themethod of accommodation, silicone oil disposed within an accommodatingIOL can be adapted to be moved within the IOL when the bulk polymericmaterial changes shape. Properties of the silicone oil can thereforeaffect the accommodative response time of the IOL. Improved fluids(e.g., silicone oils) and their methods of use in accommodatingintraocular lenses are therefore needed.

SUMMARY OF THE INVENTION

The present disclosure relates to ophthalmic devices including IOLs andmore particularly to accommodating intraocular lenses (accommodatingIOLs) including a silicone oil disposed within the chamber of the lens.In one aspect, an intraocular lens (IOL) having an optical axisextending in an anterior-posterior direction and an equator extending ina plane substantially perpendicular to the optical axis is provided. TheIOL includes: an elastic anterior face located anterior to the equator;a posterior face located posterior to the equator, wherein the anteriorface, the posterior face, or both comprises a poly(dimethylsiloxane)elastomer having a durometer between about 20 Shore A to about 50 ShoreA; and a chamber located between the anterior face and the posteriorface comprising a silicone oil comprising polysiloxanes comprisingdiphenyl siloxane and dimethyl siloxane units, the silicone oil having amaximum viscosity of about 800 cSt (i.e., mm²/s) at 25° C. In someembodiments, the IOL further comprises an elastic side wall extendingacross the equator and extending from the anterior face to the posteriorface.

In some embodiments, the poly(dimethylsiloxane) elastomer has adurometer of about 50 Shore A. In additional embodiments, the anteriorand posterior face of the IOL comprise polysiloxane that is at least 99%poly(dimethylsiloxane) elastomer. In further embodiments, the anteriorface and the posterior face have one or more surfaces that are highlysmooth. In yet further embodiments, at least a portion of the anteriorface and the posterior face are coated with a layer of parylene.

The silicone oil disposed within the chamber of the lens can have avariety of different characteristics. In one embodiment, the siliconeoil has a viscosity between about 400 cSt at 25° C. to about 800 cSt at25° C. In another embodiment, the silicone oil has a refractive indexbetween 1.49-1.53. In some embodiments, the silicone oil comprises lessthan 0.1% octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane,and dodecamethylcyclohexasiloxone. In further embodiment, the siliconeoil comprises long chain polysiloxane molecules. In yet furtherembodiments, the polysiloxane comprises at least 10 mol % diphenylsiloxane. In additional embodiments, the silicone oil comprises about 30mol % diphenyl siloxane and about 70 mol % dimethyl siloxane. In yetfurther embodiments, the silicone oil has a mean molecular weight from1,000 to about 3,000 Daltons.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective cross-sectional view of a shape-changing opticof an IOL according to an aspect of the present disclosure.

FIG. 2 is a side view of a shape-changing optic of an IOL according toan aspect of the present disclosure.

FIG. 3 is a perspective view of the IOL including the shape changingoptic of FIGS. 2 and 3 including a depiction of haptics according to anaspect of the present disclosure.

FIG. 4 is a perspective cross-sectional view of an IOL according toanother aspect of the present disclosure.

FIG. 5 is a side view of an IOL according to an aspect of the presentdisclosure.

FIG. 6 is a side view of an IOL according to another aspect of thepresent disclosure.

FIG. 7 is a perspective cross-sectional view of a shape-changing opticof an IOL according to an aspect of the present disclosure.

FIG. 8 is a side cross-sectional view of a shape-changing optic of anIOL according to an aspect of the present disclosure.

FIG. 9 is a is a side cross-sectional view of a shape-changing optic ofan IOL according to an aspect of the present disclosure

FIG. 10 is a side view of an IOL according to another aspect of thepresent disclosure.

FIG. 11 is a side view of an IOL according to another aspect of thepresent disclosure.

FIG. 12 is a side view of an IOL according to another aspect of thepresent disclosure.

FIG. 13 is a side view of a shape-changing optic of an IOL according toan aspect of the present disclosure.

FIG. 14 is a side view of an IOL according to another aspect of thepresent disclosure.

FIG. 15 is a perspective cross-sectional view of the IOL of FIG. 14according to an aspect of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an intraocular lens (IOL) having anoptical axis extending in an anterior-posterior direction and an equatorextending in a plane substantially perpendicular to the optical axis.The IOL includes: an elastic anterior face located anterior to theequator; a posterior face located posterior to the equator, wherein theanterior face, the posterior face, or both comprises apoly(dimethylsiloxane) elastomer having a durometer between about 20Shore A to about 50 Shore A; and a chamber located between the anteriorface and the posterior face comprising a silicone oil comprisingpolysiloxanes comprising diphenyl siloxane and dimethyl siloxane units,the silicone oil having a maximum viscosity of about 800 mm²/s at 25° C.

Definitions

The terminology as set forth herein is for description of theembodiments only and should not be construed as limiting of theinvention as a whole. Unless otherwise specified, “a,” “an,” “the,” and“at least one” are used interchangeably. Furthermore, as used in thedescription of the invention and the appended claims, the singular forms“a”, “an”, and “the” are inclusive of their plural forms, unlesscontraindicated by the context surrounding such. The conjunctive phrase“and/or” indicates that either or both of the items referred to can bepresent.

By “substantially” is meant that the shape or configuration of thedescribed element need not have the mathematically exact described shapeor configuration of the described element but can have a shape orconfiguration that is recognizable by one skilled in the art asgenerally or approximately having the described shape or configurationof the described element.

As used herein, the terms “anterior,” “posterior,” “superior,”“inferior,” “lateral,” and “medial” refer to the position of elementswhen a patient is in a standard anatomical position unless otherwiseindicated. The terms “left,” “right,” “top” and “bottom” refer to theposition of elements as they are depicted in the drawings and the terms“left” and “right” can be interchanged unless indicated otherwise.

The terms “first,” “second,” etc. are used to distinguish one elementfrom another and not used in a quantitative sense unless indicatedotherwise. Thus, a “first” element described below could also be termeda “second” element. A component operably coupled to another componentcan have intervening components between the components so long as theIOL can perform the stated purpose.

By “integral” or “integrated” is meant that the described components arefabricated as one piece or multiple pieces affixed during manufacturingor the described components are otherwise not separable using a normalamount of force without damaging the integrity (i.e., tearing) of eitherof the components. A normal amount of force is the amount of force auser would use to remove a component meant to be separated from anothercomponent without damaging either component.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc.).

As used herein, the term “about,” when referring to a value or range ismeant to encompass variations of in some embodiments ±10%, in someembodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, andin some embodiments ±0.1% from the specified amount (and all percentvalues therebetween), as such variations are appropriate for the IOL toperform its desired functionality.

A “subject,” as used herein, can be any animal, and may also be referredto as the patient. Preferably the subject is a vertebrate animal, andmore preferably the subject is a mammal, such as a research animal(e.g., a mouse or rat) or a domesticated farm animal (e.g., cow, horse,pig) or pet (e.g., dog, cat). In some embodiments, the subject is ahuman.

“Biocompatible” as used herein, refers to any material that does notcause injury or death to a subject or induce an adverse reaction in asubject when placed in contact with the subject's tissues. Adversereactions include for example inflammation, infection, fibrotic tissueformation, cell death, or thrombosis. The terms “biocompatible” and“biocompatibility” when used herein are art-recognized and mean that thematerial is neither itself toxic to a subject, nor degrades (if itdegrades) at a rate that produces byproducts at toxic concentrations,does not cause prolonged inflammation or irritation, or does not inducemore than a basal immune reaction in the host.

Any estimated molecular weights described herein are obtained relativeto polystyrene molecular weights standards.

Intraocular Lens

In one aspect, the present invention provides an intraocular lens (IOL)having an optical axis extending in an anterior-posterior direction andan equator extending in a plane substantially perpendicular to theoptical axis. The IOL comprises: an elastic anterior face locatedanterior to the equator; a posterior face located posterior to theequator, wherein the anterior face, the posterior face, or bothcomprises a poly(dimethylsiloxane) elastomer having a durometer betweenabout 20 Shore A to about 50 Shore A; and a chamber located between theanterior face and the posterior face comprising a silicone oilcomprising polysiloxanes comprising diphenyl siloxane and dimethylsiloxane units, the silicone oil having a maximum viscosity of about 800mm²/s at 25° C.

All IOLs as described herein are used for medical purposes and aretherefore sterile. Components of IOLs as described herein can be usedwith IOLs described herein as well as other IOLs. For example, an IOL asdescribed herein can be placed anterior to an existing, previouslyplaced IOL. IOLs include fixed power, multifocal, EDOF, diffractive andother variable focus lenses. Although the drawings show certain elementsof an IOL in combination, it should be noted that such elements can beincluded in other embodiments or aspects illustrated in other drawingsor otherwise described in the specification. In other words, each of thedisclosed aspects and embodiments of the present disclosure may beconsidered individually or in combination with other aspects andembodiments of the disclosure including patent applications incorporatedby reference herein.

Unlike shape changing accommodating IOLs described by way of background,IOLs are provided herein that can mimic the gradient elastic propertiesof a natural youthful human lens during accommodation and include ashape-changing optic where components of the optic change shape as theIOL transitions from an accommodated state to a dis-accommodated stateand vice versa. Without wishing to be bound by a specific mechanism ofaction, it is considered by some that the lens capsules' “elasticity”controls and shapes the lens as a whole (the lens nucleus and cortex).On this basis, the lens contents are considered pliable. However, thevolume of the lens contents compared to the thickness and known modulusof elasticity of the lens capsule predicts that the lens capsule cannotsolely control and alter the shape of the lens nucleus and cortex.Finite element analysis (FEA) predicts that radial tension about theequatorial region of a lens capsule filled with a soft pliable solid orliquid does not result in significant shape change to either theanterior or posterior surface of the lens compared to what is known tooccur with the natural youthful human lens. Providing radial tensiondirected specifically to at least the anterior face of an accommodatingIOL; having that tension directed at points anterior to the equator ofthe IOL; the anterior face of the IOL being more resistant todeformational change than the content(s) of a chamber underlying theanterior face; the anterior face demonstrating elastic properties in somuch as the anterior face deforms when a force is applied to theanterior face and the anterior face will return to its original shapewith the removal of the force, results in a greater amount of anteriorface shape change and therefore accommodating dioptric power change thancan be achieved with a similar force applied at points at or more nearthe equator of the IOL (e.g. equatorial). In addition, a force appliedto the anterior face at points anterior to the equator of the IOLrequires less diameter change of the anterior face per diopter of powerchange of the IOL compared to a similar force applied at points at ormore near the equator of the IOL thereby allowing the anterior face ofthe IOL to shape change even with very small amounts of anterior facediameter change when going from an accommodated state, adis-accommodated state, and states in between.

In particular, in an aspect, an IOL comprising a shape changing opticthat can assume an accommodated state, a dis-accommodated state, andstates therebetween is provided. Components of the shape-changing opticcan be deformable such that ocular compression force or tensile forceapplied to the optic caused by ciliary muscle contraction or relaxationcauses one or more components of the optic to change shape and allowsthe optic to change dioptric power. As such, components of ashape-changing optic can deform or change shape when a force is applied.If a component is less resistant to deformational change than anothercomponent, the former component is more likely to, or to a greaterdegree, deform for a given amount of applied or removed force than thelatter component. A component is more resistant to deformational changethan another component, if the former component is less likely to, or toa lesser degree, deform for a given amount of applied or removed forcethan the latter component. It is understood that for any given componentresistant to deformational change, the force applied/removed to suchcomponent does not exceed the force that results in breakage of thecomponent such that it is no longer useful for its therapeutic purpose.

FIG. 2 depicts a central or optical axis CA extending in ananterior-posterior direction and an equator E extending in a planesubstantially perpendicular to the central axis. The equator is animaginary line drawn around the circumference of a lens perpendicular tothe optical axis, equally distant from the anterior face of the lens andthe posterior face of the lens, dividing the lens into an anterior halfand a posterior half. Referring to FIGS. 1-3, a shape-changing optic 12of an IOL 10 can comprise an elastic anterior face 14 located anteriorto equator E. Anterior face 14 can have an anterior surface 16, aposterior surface 18 and a periphery 20. Shape-changing optic 12 canalso comprise a posterior face 22 having an anterior surface 24, aposterior surface 26, and a periphery 28. Shape-changing optic 12 canfurther include an elastic side wall 30 extending across equator E andextending from anterior face 14 to posterior face 22. A chamber 32 canbe located between anterior face 14 and posterior face 22 and can housematerial or contents as described in more detail below. Components ofthe shape-changing optic can be made to be more or less resistant todeformational change by altering the thickness of the component, thetype of material from which the component is fabricated, or by alteringthe chemical/material properties of the component material itself forexample. With reference to FIG. 3, IOL 10 can further comprise at leastone haptic 34 extending from the periphery of the anterior face. Atleast one haptic can also extend from the periphery of the posteriorface, or the periphery of both the anterior face and the posterior faceas described below.

Regarding specific components of an IOL, the anterior face, as statedabove, can have elastic properties. Elastic properties can allow for theanterior face to change shape with an applied force, but also to returnto its original configuration when the force is removed. It isbeneficial that the anterior face be more resistant to deformationalchange (e.g. less pliable, firmer) than the contents or materialcontained within the chamber because when an outward radial force isapplied to the anterior face, the contents of the chamber can moreeasily deform to allow flattening of the anterior face. Exemplaryfabrication materials for the anterior face include silicone (i.e.,polysiloxane), an acrylic (hydrophobic or hydrophilic) polymer,polymethylmethalcryalate (PMMA), silastic, collamer, a suitable opticalthermoplastic polymer, another suitable optical material, and suitablecombinations thereof.

Regarding the posterior face of the shape-changing optic, the posteriorface can be more resistant to deformational change than the anteriorface or the contents contained within the chamber of the shape-changingoptic. The posterior face need not have the ability to change shape.When implanted and in certain aspects, the posterior face can restagainst the posterior capsule and the vitreous substance and it may notbe desirable to have those less predictable forces altering the power ofthe optic. Further, having a posterior face that is more resistant todeformational change than the anterior face or the contents of thechamber of the shape-changing optic can allow the posterior face opticto have a relatively more fixed power posterior lens permitting theincorporation of beneficial optical properties. In addition, a posteriorface more resistant to deformational change can allow the contents ofthe chamber to reshape the side wall(s) when the anterior face changesshape in response to a force. The posterior face can be part of aone-piece integral IOL 10 as depicted in FIG. 1-3 or can be a two-pieceintegral IOL 10A as illustrated in FIG. 4-6. In certain aspects, theposterior face is elastic. Exemplary fabrication materials for theposterior face include silicone (i.e., polysiloxane), an acrylic(hydrophobic or hydrophilic) polymer, polymethylmethalcryalate (PMMA),silastic, collamer, a suitable optical thermoplastic polymer, anothersuitable optical material, or suitable combinations thereof. Theposterior face can comprise a lens with a variety of optical properties,such as, for example, a spherical, aspheric, toric, toroidal,multifocal, diffractive, extended depth of focus, or combinationsthereof. As illustrated in FIG. 6, an IOL 10B can comprise ashape-changing optic where the posterior face 22B has a squaredperipheral edge 35 to reduce posterior capsular opacification, byinhibiting, for example, peripheral lens epithelial cells from migratingacross the posterior face.

In some embodiments, the anterior face and/or the posterior face mayhave one or more surfaces that are highly smooth (i.e., has a lowsurface roughness). The smoothness of the surface is determinedprimarily by the smoothness of the mold used to prepare the anteriorand/or posterior face. The finish on the molds should be of sufficientquality to produce a finish that meets the international standards ofoptics for intraocular lenses. As such, the finish on the molds shouldbe at least SPI A-3, more preferably A-2, and yet more preferably A-1.SPI A-1 corresponds to 6000 grit, SPI A-2 corresponds to 3000 grit, andSPA A-3 corresponds to 1200 grit. If the surfaces are not smooth, oneneeds to match the refractive index of the shell polymeric material andthe silicone oil to avoid optical interface aberrations. Smoothness, orsurface roughness, can be measured using a contact-type roughnesstester, an atomic force microscope, a while light interferometer, or alaser microscope, which provide resolutions from 1 nm to 0.1 nm.

Regarding the side wall, as stated above, the side wall can have elasticproperties. In certain aspects, the side wall can be fabricated from amaterial that is equal to or less resistant to deformational change thanthe anterior face. Such features can allow for the contents containedwithin the chamber to expand the area of the side wall to allow thevolume of the contents of the chamber to remain the same when theanterior surface is flattened. Having the side wall deform canfacilitate and allow for a greater amount of shape change to theanterior face of the shape-changing optic. Exemplary fabricationmaterials for the side wall include silicone, an acrylic (hydrophobic orhydrophilic) polymer, polymethylmethalcryalate (PMMA), silastic,collamer, a suitable optical thermoplastic polymer, another suitablematerial, or a suitable combination thereof. The side wall can also beequal to or less resistant to deformational change than the anteriorface or the posterior face by being thinner than the anterior face orthe posterior face. Alternatively, or in addition, the side wall 36 of ashape-changing optic 38 can be equal to or less resistant todeformational change by having a bellowed configuration as illustratedin FIG. 7. The bellows can be horizontally or vertically oriented orhave other orientations to allow for peripheral side wall expansion orcontraction. As illustrated in FIG. 8, the side wall 90 of a shapechanging optic 92 can have a plano, concave, convex, or otherconfiguration to facilitate displacement of the contents of chamber 94against side wall 90 when anterior face 96 is flattened.

Regarding the chamber, the chamber can be defined by the posteriorsurface of the anterior face, the anterior surface of the posteriorface, and an inner surface of the side wall. The interior contents ormaterial of the chamber can comprise a soft solid, a gel, a viscoelasticmaterial, a flowable fluid, or a gas, or other suitable material.Exemplary materials that can be contained within the interior of thechamber include a soft silicone, or other soft material subject todeformational change, air or other gas, silicone oil (of variousrefractive indices), an aqueous solution of saline or hyaluronic acid, aviscoelastic polymer, polyphenyl ether, or other optical fluid, solid orgases, or suitable combinations thereof. The chamber can have aninternal layer or coating to seal the contents of the chamber from theanterior face, the side wall and/or the posterior face. The chamber canbe pre-loaded (e.g. by a manufacturer) with a suitable material.Alternatively, the chamber can be loaded with a suitable material by aclinician. For example, and with reference to FIG. 9, a shape-changingoptic 40 of an IOL can define at least one port 42 (enlarged in FIG. 9for purposes of clarity) sized and dimensioned to receive a needle orcatheter, the needle or catheter being sized and dimensioned to delivera fluid, gel, or gas to the chamber and/or to exchange fluid with adifferent material or a material having a different refractive index,for example. Although FIG. 9 illustrates the port defined by anteriorface 44, the port can be defined by the side wall 46 or the posteriorface 48 of the shape-changing optic. Having a port can allow a user toadd or remove substance from chamber 47 to adjust the optical power ofthe lens. For example, by adding additional substance to the chamber,the volume of the substance can increase in the chamber resulting in anincrease in the surface(s) curvature and the overall power of the lensand removing substance can decrease the volume of the substance in thechamber resulting in a decrease in the surface(s) curvature and theoverall power of the lens. Also, by exchanging the substance for onewith a different refractive index, the overall dioptric power and therange of accommodation of the IOL can be increased or decreased.

Regarding the at least one haptic of the IOL, such a haptic(s) is theportion of the IOL that is configured to interact with the lens capsule,the lens zonules, the ciliary muscle, or other parts of a patient's eye.The at least one haptic can be molded, shaped into, integral with, orotherwise extend from the shape-changing optic of an IOL. As illustratedin FIG. 3, the at least one haptic can comprise a plurality of hapticsdisposed about the circumference of the anterior face of theshape-changing optic. The at least one haptic can be elastic but can bemore resistant to deformational change than the anterior face. Anadvantage to this is that the haptic can be firmer to provide a linearforce from the haptic to the periphery of the anterior face. Withoutwishing to be bound by any particular mechanism of action, if the hapticwere to be less resistant to deformational change than the anteriorface, the radial tension could result in stretching of the haptic andless tension on the periphery of the anterior face. Thus, the anteriorface may not shape change as much for a given force applied to thehaptic. Exemplary fabrication materials for the at least one hapticinclude silicone, an acrylic (hydrophobic or hydrophilic) polymer,polymethylmethalcryalate (PMMA), silastic, collamer, a suitable opticalthermoplastic polymer, another suitable material, or suitablecombinations thereof.

Regarding the haptics, in certain aspects, each of the plurality ofhaptics is non-rotatable in response to axial compression along theoptical axis on the shape-changing optic. In certain aspects, each ofthe haptics has a peripheral portion having a posterior face and ananterior face, with the posterior face being curved. In other aspects,the medial portion of each of the plurality of haptics medial portionextends from and is connected to the periphery of the anterior face suchthat the plurality of haptics changes the shape of the anterior face viaapplication of radial force to the periphery of the anterior face in adirection perpendicular to the optical axis and not via axialcompressive forces along the optical axis on the shape-changing optic orvia axial compressive forces on the haptics.

FIGS. 3 to 6 illustrate an IOL where at least one haptic extends fromthe anterior face of a shape-changing optic. The shape-changing opticcan change shape in response to an ocular force, specifically a forcegenerated by the contraction or relaxation of the ciliary muscle of thepatient's eye. The at least one haptic, interacting with the lenscapsule, can apply radial outward tension to the anterior face when theciliary muscle relaxes and radial outward tension is placed on the lenscapsule via the lens zonules. The at least one haptic can be elastic butcan be equal to or more resistant to deformational change than theanterior face.

FIG. 3 illustrates an aspect where a plurality of haptics extendscircumferentially from the shape-changing optic. When implanted and whenthe ciliary muscles of a patient's eye relaxes (such as when the eye isin a dis-accommodated state), the ciliary muscles apply tensile force tothe plurality of haptics (via the lens capsule with lens zonuleattachments between the lens capsule and the ciliary muscles, forexample). The plurality of haptics, in turn, can apply tensile force tothe periphery of the anterior face at each site (referred to herein asan “extension site”) where a haptic extends from the periphery of theanterior face. By having a plurality of haptics as depicted in FIGS. 3and 4, the net result can be that the anterior face can be pulledoutward from several extension sites (such as, for example, eightextension sites as illustrated in FIG. 3) and functionally result inrelatively symmetric radial tension placed on the periphery of theanterior face of the shape-changing optic. Referring to FIG. 10, incertain aspects, an IOL 70 includes at least one haptic 72 extendingfrom posterior face 74 of shape-changing optic 76. By having the forceapplied to the posterior face, a change in shape of the optic can beachieved independent of or in combination with a force applied to theanterior face. Referring to FIG. 11, in other aspects, an IOL 78includes at least one haptic 80 extending from anterior face 82 andposterior face 84 of shape-changing optic 86. If a force is applied toboth the posterior and the anterior faces, the total dioptric powerchange of the IOL for a given force can be increased. In other words, ifa force is applied to both the anterior and posterior face, shape changecan be obtained to both surfaces and thereby increase overallaccommodation.

The at least one haptic can engage the inner surface of the lens capsuleor the outer surface of the lens capsule. Referring to FIGS. 3-6, theperipheral portion of the at least one haptic 34 can comprise ridges 50as illustrated in FIGS. 3-6 configured to engage an inner surface of alens capsule. For example, ridges 50 can interact with the lens capsuleto stabilize the haptics within the lens capsule. Ridges can also allowthe haptics to interact and fixate into the lens capsule. Such an aspectcan allow IOL placement within the capsular bag, while still allowingtranslation of tension/relaxation of the lens capsule (via the lenszonules and ciliary body) during accommodation/dis-accommodation of thelens. Current haptic designs do not allow the haptics to be positionedwithin the lens capsule while fixating the haptics to allowtension/relaxation on the lens capsule to translate forces into thehaptics. Current haptic designs are smooth and allow the capsule andhaptic to glide past each other, which does not allow the translation offorces placed on the peripheral lens capsule (via the zonules andciliary muscle). When placing the IOL inside the capsular bag, theridge(s) can be configured to allow the IOL to be rotated until thedesired rotational position of the IOL is achieved. Once the IOL isrotated into its desired position, the forces on the haptics fixatelateral portions of the haptics to the inside peripheral edge of thelens capsule. The ridges then provide resistance to these forces andfacilitate the forces from the ciliary body, zonules, and lens capsuleinto a force on the haptic(s).

Regarding the at least one haptic engaging the outer surface of the lenscapsule, when an IOL is placed anterior to an existing, previouslyimplanted IOL, or when placed anterior to the lens capsule, the at leastone haptic can engage the outer surface of the lens capsule. Referringto FIG. 12, the peripheral portion of haptic 52 of an IOL 53 cancomprise a hookshaped/substantially J-shaped configuration to engage orcurve around an outer surface of a lens capsule. The peripheral end ofthe peripheral portion can be an atraumatic end so that it does notdamage zonules or the lens capsule. The at least one haptic (for examplethe right haptic and/or the left haptic) can each comprise a pluralityof hooks. Hook or substantially J-shaped haptics can allow an IOL to usethe force translated from the ciliary muscle to the lens capsule, viathe lens zonules, without requiring placement of haptics againstelements of the ciliary muscle. Such an embodiment can avoid knownpotential complications of haptics placed against the ciliary muscle,such as uveitis, glaucoma, and bleeding (e.g. hyphema). Such anembodiment can be implemented in patients that have an already implantedIOL or patients that do not have an already implanted IOL.

Referring to FIG. 13, the shape-changing optic itself can define ridgesto engage the inner surface of a lens capsule. For example, theshape-changing optic 56 can include an expandable chamber 57, that hasan integrated haptic with ridges 58 and 60 on periphery 59 of theanterior face 62 and/or the periphery 61 of the posterior face 64. Whentension is placed on the lens capsule by the zonules (e.g. when theciliary muscle relaxes), the force can be translated (by the ridgesengaging the capsule) specifically to the anterior and posterior facesand not just translation of a general force to the entire lens. Theanterior face, the posterior face, and/or the side walls can be moreresistant to deformational change than the contents of the chamber. Thisconfiguration can allow forces from the lens capsule to provide radialtension to the haptics and thus to the anterior face, the anterior facebeing anterior to the equator of the lens; and/or to provide radialtension to the posterior face, the posterior face being posterior to theequator of the lens. The side walls can be configured to allow for thematerial in the chamber displaced by the flattening of the anterior faceand/or the posterior face to expand into the area of the side wall,thereby allowing the volume of material within the chamber to remain thesame.

Referring to FIGS. 14 and 15, in certain aspects, an IOL 100 is providedwhere the bottom of haptic 102 defines a recess 104. Such a recess canaccommodate a stabilizing ring 106, for example, to keep the hapticsfrom holding inwards with lens capsule fibrosis. Stabilizing ring can befabricated from any of the materials described above with respect to theanterior and/or posterior faces of the shape changing optic.

The IOL includes an optical axis extending in an anterior-posteriordirection and an equator extending in a plane substantiallyperpendicular to the optical axis. The IOL can further comprise anelastic anterior face located anterior to the equator and a posteriorface located posterior to the equator. The anterior face, the posteriorface, or both can comprise a poly(dimethylsiloxane) elastomer having adurometer between about 20 Shore A to about 70 Shore A, which is ameasure of the hardness of the material. Hardness is related toresistance to deformation change, and therefore the greater the Shorenumber, the more resistant the material is to deformation. In someembodiments, the elastomer has a durometer between about 20 Shore A toabout 50 Shore A. In further embodiments, the durometer can be betweenabout 30 Shore A to about 50 Shore A. In a yet further embodiment, thedurometer can be about 50 Shore A. Providing an anterior and posteriorface having a suitable hardness allow the material to be stiff enough todisplace the fluid in the chamber, strong enough not to tear, and havingsufficient elasticity to reshape smoothly over the surface. In someembodiments, the anterior and posterior face are made of material havinga tensile strength from about 1.8 mPa to about 8.6 mPa., and morepreferably from about 4 mPa to about 6 mPa.

The IOL can further include a chamber located between the anterior faceand the posterior face and can comprises a silicone oil comprisingpolysiloxanes comprising diphenyl siloxane and dimethyl siloxane units.The polysiloxanes can comprise end blocking groups of trimethylsiloxane.The silicone oil can have a maximum viscosity of about 800 mm²/s at 25°C., including a viscosity between about 400 mm²/s at 25° C. to about 800mm²/s at 25° C. In certain embodiments, the silicone oil can have a meanmolecular weight of less than about 3,000 Daltons. It should be notedthat this described embodiment can include all the features and aspectsdescribed in all other embodiments and aspects of the presentdisclosure.

An IOL having such features has several advantages. By way ofbackground, in a natural, healthy eye, a lens capsule deforms the lenscortex and lens nucleus (the lens contents) by virtue of the lens cellsdeforming. This is because the cytosol within each individual lens cellis free flowing and, in aggregate, the lens contents acts like aflowable fluid. Accordingly, the lower the viscosity of the fluid withinthe chamber of the IOL, the easier it is for the fluid to move inresponse to force applied by the anterior face and/or the posterior faceof the IOL. As such and by way of example with respect to the anteriorface, the anterior face comprising a poly(dimethylsiloxane) having adurometer between about 20 Shore A to about 50 Shore A in combinationwith a chamber containing a silicone oil having a maximum viscosity ofabout 800 mm²/s at 25° C. and having a mean molecular weight of lessthan about 3000 Daltons allows the anterior face to be more resistant todeformational change than the contents of the chamber underlying theanterior face, allows the anterior face to demonstrate elasticproperties such as deforming when a force is applied to the anteriorface and returning to its original shape when the force is removedresulting in an effective amount of anterior face shape change andtherefore accommodating dioptric power change. Such an IOL more closelymimic the elastic gradient of a natural youthful human lens duringaccommodation particularly when radial tension is directed specificallyto at least the anterior face and the tension is directed at pointsanterior to the equator of the IOL. Further, an anterior and/orposterior face comprising a poly(dimethylsiloxane) having a durometerbetween about 20 Shore A to about 50 Shore A has sufficient tearstrength necessary to mold the lens during manufacturing. In certainembodiments, the IOL can include an elastic side wall extending acrossthe equator and extending from the anterior face to the posterior face.The elastic side wall can also have a durometer between about 20 Shore Ato about 50 Shore A, in addition to the anterior face and/or theposterior face having such a durometer value range.

In certain aspects, the present disclosure provides an IOL that has anoptical axis extending in an anterior-posterior direction and an equatorextending in a plane substantially perpendicular to the optical axis.The IOL can comprise an elastic anterior face located anterior to theequator and a posterior face located posterior to the equator. Theanterior face, the posterior face, or both can comprise a polysiloxanethat is at least 99% poly(dimethylsiloxane) elastomer. In other words,the polysiloxane can have no phenyl units, trace amounts of phenylunits, or immeasurable amounts of phenyl units such that the IOLachieves its desired functionality as described herein. The IOL canfurther comprises a chamber located between the anterior face and theposterior face. The chamber can comprise a silicone oil comprisingpolysiloxanes comprising diphenyl siloxane and dimethyl siloxane units.In certain embodiments, the polysiloxanes comprise at least about 30mole % diphenyl siloxane, because polymer chains without phenyl groupscan absorb into the poly(dimethylsiloxane). In certain embodiments, theIOL can further comprise an elastic side wall extending across theequator and extending from the anterior face to the posterior facewherein the elastic side wall also comprises a polysiloxane that is atleast 99% poly(dimethylsiloxane), in addition to the posterior faceand/or anterior face having this % poly(dimethylsiloxane). It should benoted that this described embodiment can include all the features andaspects described in all other embodiments and aspects of the presentdisclosure. An anterior face, posterior face and/or side wall comprisingpolysiloxane that is at least 99% poly(dimethylsiloxane) minimizesabsorption of the silicone oil described herein into the anterior face,the posterior face, and/or the side wall. This is important becauseabsorption of the silicone oil into the anterior face, the posteriorface and/or the side wall can increase the thickness and weight of theanterior face, the posterior face and/or the side wall. This can changethe mechanical and optical properties of the anterior face, theposterior face and/or the side wall such as the elastic properties, theoptical clarity and the refractive index of the IOL.

In some embodiments, at least a portion of the anterior face and theposterior face are coated with a layer of parylene. In some embodiments,the entire anterior face and the posterior face are coated with a layerof parylene, while in further embodiments only the surfaces in contactwith silicone oil are coated with parylene. Parylenes are polymers whosebackbone consists of para-benzenediyl rings connected by 1,2-ethanediylbridges. Examples of parylenes include Parylene N, chlorinatedparylenes, fluorinated parylenes, and alkyl-substituted parylenes.Preferably only a thin layer of parylene is applied to the opticalsurfaces in contact with the silicone oil. Parylene provides a barrierto fluid and/or oil absorption into the silicone.

Each of the disclosed aspects and embodiments of the present disclosuremay be considered individually or in combination with other aspects andembodiments as well as with respect to other intra-ocular lenses, suchas IOLs disclosed in U.S. Pat. No. 10,898,316, which is incorporated byreference in its entirety. In addition, orientations of a shape-changingoptic can be modified. For example, when implanted, the lens can beflipped such that the anterior face is facing in a posterior directionand the posterior face is facing in an anterior direction. Further, theIOL can be configured such that it is foldable for insertion. Further,while certain features of embodiments may be shown in only certainfigures, such features can be incorporated into or deleted from otherembodiments shown in other figures or otherwise disclosed in thespecification. Additionally, when describing a range, all points withinthat range are included in this disclosure.

One aspect of the disclosure is a method of manufacturing an intraocularlens by assembling a bulk polymer material and the silicone oil to forman intraocular lens. The assembling step can comprise advancing thesilicone oil into a fluid chamber within the bulk material of theintraocular lens. The silicone oil can have been purified to have a meanmolecular weight between about 1,000 Daltons and about 3,000 Daltons. Insome embodiments the silicone oil has a refractive index at least 0.2greater than the bulk polymeric material.

Silicone Oil for the IOL Chamber

The disclosure herein generally relates to fluid, such as silicone oil,that is used in an intraocular lens. While silicone oils used inaccommodating IOLs are primary described herein, it is possible to useany of the silicone oils in a non-accommodating IOL. For example, anon-accommodating IOL can have a relatively rigid outer polymeric shellsurrounding a silicone oil core. In some embodiments the silicone oil isused in an accommodating intraocular lens that uses movement of the bulkpolymeric material enclosing the silicone oil to effect optical powerchange in the IOL. The silicone oil can, however, be used innon-accommodating intraocular lenses as well.

Swelling of the bulk polymeric material should be taken intoconsideration when selecting a silicone oil for use in the IOL. Whensilicone oil is used in accommodating IOL with a bulk material such as apolymeric material, some of the oil components can pass into the bulkmaterial, causing the bulk material to swell. The silicone oil generallyneeds to be selected or designed in such a way as to avoid adverseinteractions with the surrounding bulk IOL material, such as swelling,fogging, dissolving or reacting with the material (e.g., poly acrylate)in some IOLs. The degree of solubility of the silicone oil in the bulkmaterial is dependent on the chemical structure and molecular weightdistribution of the silicone oil. Other parameters that influence thisinteraction are the composition and properties of the bulk material suchas homogeneity, chemical structure, hydrophobicity, modulus, andcrosslink density. Thus, the silicone oil should have a differentcomposition from the bulk polymer that decreases mixture of the siliconeoil with the bulk polymer. For example, if the bulk polymeric materialis dimethyl siloxane without phenyl groups, and the silicone oil is adimethyl/diphenyl siloxane such that an increased percentage of themolecules in the silicone oil contain phenyl groups, then swelling ofthe bulk dimethyl silicone material is minimized.

The silicone oil included in the IOL should be selected or manufacturedto provide one or more advantages such as avoid interaction (e.g.swelling) with the bulk dimethyl polymeric material of the intraocularlens. A variety of traits of the silicone oil can be selected to avoidinteraction with the bulk dimethyl polymeric material. These include anincreased percentage of diphenyl siloxanes, a silicone oil having a verylow level of impurities, an increased amount of long chain siliconemolecules, a different molecular weight, and a viscosity and/orrefractive index within a preferred range.

Some IOLs rely on or can benefit from a silicone oil comprising diphenylunits. Chain polysiloxanes are composed of difunctional units. Theframing groups (R) are either H or organic moieties and the end groupsare usually —OR or a monofunctional siloxyl unit. Chain polysiloxanessuch as poly-(dimethylsiloxane)s are synthesized by the hydrolysis ofdichlorodimethysilane. Diphenyl groups, in with the R group is a phenylgroup, can be included in the polysiloxane using essentially the samechemistry. A chemical structure of a polysiloxane including bothdimethylsiloxane and diphenyl siloxane is shown in Scheme 1.

Dimethyl/diphenyl silicone oils can be produced by increasing the eitherthe percentage of molecules with phenyl groups attached and/or byincreasing the number of phenyl groups in each molecule. In someembodiments, each dimethyl/diphenyl copolymer includes at least onephenyl group. Silicone oils with an increased percentage ofpolysiloxanes including phenyl groups can be used with a pure dimethylbulk polymeric material. When an increased percentage of the siliconeoil includes diphenyl units, the tendency for the silicone oil to beabsorbed (swell) into the surrounding dimethyl polysiloxane bulkmaterial is reduced.

Silicone oils including diphenyl units can have a variety of differentmole percent of diphenyl units in comparison with the dimethyl unitspresent in the polysiloxane. In some embodiments, the polysiloxanecomprises at least 1 mol % diphenyl siloxane, at least 2 mol % diphenylsiloxane, at least 5 mol % diphenyl siloxane, at least 10 mol % diphenylsiloxane, at least 15 mol % diphenyl siloxane, at least 20 mol %diphenyl siloxane, at least 25 mol % diphenyl siloxane, at least 30 mol% diphenyl siloxane, at least 35 mole % diphenyl siloxane, at least 40mol % diphenyl siloxane, at least 45 mol % diphenyl siloxane, or atleast 50 mol % diphenyl siloxane.

The relative amount of diphenyl units included in the polysiloxane canalso be expressed as a range, with the reminder of the polysiloxaneconsisting of dimethyl units. In some embodiments, the silicone oilcomprises from about 1 mol % to about 50 mol % diphenyl units, about 1mol % to about 30 mol % diphenyl units, about 2 mol % to about 50 mol %,about 2 mol % to about 40 mol %, about 5 mol % to about 40 mol %, about10 mol % to about 40 mol %, about 20 mol % to about 40 mol %, or about25 mol % to about 35 mol %. In some embodiments, the silicone oilcomprises about 30 mol % diphenyl siloxane and about 70 mol % dimethylsiloxane.

The silicone oil preferably also includes a low or very low level ofimpurities. In some embodiments, the silicone oils described herein havea very low concentration of small cyclic volatile methyl siloxane (cVMS)molecules (e.g., D4-D6 molecules), that include a small number (e.g.,4-6) siloxane groups. The chemical name for the specific D4-D6 moleculesare octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane(D5), and dodecamethylcyclosiloxane (D6). It is desirable to have asilicone oil with less than 0.1% of small cyclic species (D4-D6molecules). In some embodiments, the silicone oil comprises less than0.05% of small cyclic species (D4-D6 molecules). In addition, thesilicone oil should be clear, colorless, have less than about 10 ppmheavy metals and other insoluble inorganics contaminants, and havesubstantially no silanols.

Removal of silicone oil components that dissolve into the bulk IOLmaterial over time (e.g., during storage) may be accomplished byexposing the silicone oil to bulk quantities of the IOL material, orother materials that have been selected for that purpose. On storagewith an appropriate material, the components of the silicone oil thatdissolve into the bulk IOL polymeric material may be removed byadjusting the ratio of silicone oil to polymer adsorbent so thatsufficiently low levels of those materials remain in the oil.

In may also be desirable to include some long chain polysiloxanemolecules in the silicone oil. Long or very long chain polysiloxanemolecules can help stabilize the silicone oil and reduce the potentialfor emulsification. Accordingly, in some embodiments the silicone oilcomprises long or very long chain polysiloxane molecules. In someembodiments, the silicone oil comprises from about 5% to about 10% longchain polysiloxane molecules by weight. Long chain polysiloxanemolecules (i.e., long chain aralkyl silicone oil) is available from avariety of commercial sources, such as Iota Silicone Oil. Ltd.

In some embodiment's silicone oil is provided that includes smallerpolymers having a mean molecular weight of less than about 3,000Daltons, or between about 1,000 and about 3,000 Daltons. In general, thesmaller molecular size of silicone oil polymers correlates with a lowerviscosity of the silicone oil. Viscosity relates to the ease with whichmolecules in a fluid can move past each other, and smaller moleculeshaving a lower molecular weight interact less, causing a decrease inviscosity. It is desirable to have a low viscosity of silicone oil inthe fluid chamber of an accommodating IOL to allow a faster responsetime during accommodation/dis-accommodation. In some embodiments, thesilicone oil has a mean molecular weight of less than about 2,500Daltons. In further embodiments, the silicone oil has a mean molecularweight of less than about 2,000 Daltons. In further embodiments, thesilicone oil is provided that has a mean molecular weight between about1,500 and about 3,000 Daltons. In a yet further embodiment, the siliconeoil has a mean molecular weight between about 2,000 and about 3,000Daltons. In an additional embodiment, the silicone oil has a meanmolecular weight between about 1,500 and about 2,500 Daltons. In afurther embodiment, the silicone oil has a mean molecular weight fromabout 1,750 to about 2,750 Daltons. In a yet further embodiment, thesilicone oil has a mean molecular weight from about 2,000 to about 2,500Daltons. Higher molecular weight silicone oils can have acorrespondingly high viscosity, which can reduce the response time ofthe accommodating IOL. Use of silicone oils having a lower molecularweight is particularly efficient when paired with a bulk polymericmaterial that is relatively firm, such as poly(dimethylsiloxane)elastomer having a durometer between about 20 Shore A to about 50 ShoreA.

Another property of the silicone oil is its polydispersity index (PDI),which is a measure of the spread of the molecular weights of thesilicone oil (i.e., the heterogeneity of sizes of the polymermolecules). The larger the PDI, the broader the range of molecularweights of the polymers. The PDI of the silicone oil used in the IOLsdescribed herein can have a value of 1.5 or more, or 2.0 or more. Insome embodiments, the PDI of the silicone oil has a value from about 1.5to about 2.0, from about 2.0 to about 3.0, or from about 1.5 to about2.5. In further embodiments, the PDI of the silicone oil has a valuefrom about 2.3 to about 2.7.

In embodiments in which the bulk polymeric material changes shape inresponse to ciliary muscle forces applied to the lens capsule via thezonules and the accommodating IOL operates dynamically, the IOL musthave an appropriate response time. This requires that the viscosity ofthe silicone oil have certain defined characteristics. Accordingly, insome embodiments the viscosity of the silicone oil is less than about800 centistokes (cSt) at 25° C. In further embodiments, the silicone oilhas a viscosity between about 600 cSt at 25° C. to about 800 cSt at 25°C. In further embodiments, the silicone oil has a viscosity betweenabout 400 cSt at 25° C. to about 800 cSt at 25° C. The viscosity ofsilicone oil can be determined using, for example, a digital viscometer.

It is desirable in some instances to have a silicone oil with arefractive index greater than the refractive index of the bulk polymericmaterial. In some embodiments it is desirable to have a silicone oilwhere the refractive index is at least 0.2 greater than the refractiveindex of the bulk polymeric material. Note that the refractive index ofpoly(dimethylsiloxane), which can be used as the bulk polymericmaterial, has a refractive index of 1.41. A higher refractive index ofthe silicone oil increases the dioptric power of the IOL, allowing alower profile (smaller A-P dimension). Dioptic power is a measure of theconvergence or divergence of light created by a lens or optical system.In addition, the higher refractive index of the silicone oil allows forsmall changes in the shape of the bulk polymeric material to result inlarger dioptric power changes of the IOL duringaccommodation/disaccommodation. A higher refractive index of thesilicone oil also allows the IOL to have a smaller anterior posteriorprofile, which facilitates placement of the IOL in the eye through asmaller incision in the eye. Examples suitable for use with apoly(dimethylsiloxane) shell would include a silicone oil with arefractive index of between about 1.45 and about 1.55, or about 1.49 andabout 1.53. The refractive index can be determined using arefractometer.

The use of a silicone oil including a higher relative diphenyl contentprovides a silicone oil having a higher refractive index and can alsoresult in the silicone oil having a lower viscosity which facilitatesrapid response times to accommodation/dis-accommodation.

In some embodiments the silicone oil has a chromatic dispersion lessthan or equal to about 0.035 refractive index units in the visible rangeof 400 nm to 750 nm at 35° C. In some embodiments the silicone oilcomponents are fully miscible with each other without evidence of phaseseparation (i.e., cloudiness or suspensions). In some embodiments thesilicone oil has greater than 85% transmittance in the range of 400 nmto 1100 nm for about a 1 cm thick fluid sample.

The silicone oil can have a plurality of the characteristics describedherein. For example, the accommodating intraocular lens comprising abulk dimethyl polymeric material can include a silicone oil comprisingdiphenyl siloxane and dimethyl siloxane with an index of refractionbetween about 1.49 and about 1.53, a mean molecular weight numberaverage of between about 1,000 Daltons to about 3,000 Daltons, and aviscosity less than about 800 cSt at about 25° C.

The complete disclosure of all patents, patent applications, andpublications, and electronically available materials cited herein areincorporated by reference. Any disagreement between materialincorporated by reference and the specification is resolved in favor ofthe specification. The foregoing detailed description and examples havebeen given for clarity of understanding only. No unnecessary limitationsare to be understood therefrom. The invention is not limited to theexact details shown and described, for variations obvious to one skilledin the art will be included within the invention defined by the claims.

What is claimed is:
 1. An intraocular lens (IOL) having an optical axisextending in an anterior-posterior direction and an equator extending ina plane substantially perpendicular to the optical axis, the IOLcomprising: an elastic anterior face located anterior to the equator; aposterior face located posterior to the equator, wherein the anteriorface, the posterior face, or both comprises a poly(dimethylsiloxane)elastomer having a durometer between about 20 Shore A to about 50 ShoreA; and a chamber located between the anterior face and the posteriorface comprising a silicone oil comprising polysiloxanes comprisingdiphenyl siloxane and dimethyl siloxane units, the silicone oil having amaximum viscosity of about 800 cSt at 25° C.
 2. The IOL of claim 1,wherein the poly(dimethylsiloxane) elastomer has a durometer of about 50Shore A.
 3. The IOL of claim 1, further comprising an elastic side wallextending across the equator and extending from the anterior face to theposterior face.
 4. The IOL of claim 1, wherein the anterior andposterior face of the IOL comprise polysiloxane that is at least 99%poly(dimethylsiloxane) elastomer.
 5. The IOL of claim 1, wherein theanterior face and the posterior face have one or more surfaces that arehighly smooth.
 6. The IOL of claim 1, wherein at least a portion of theanterior face and the posterior face are coated with a layer ofparylene.
 7. The IOL of claim 1, wherein the polysiloxane comprises atleast 10 mol % diphenyl siloxane.
 8. The IOL of claim 1, wherein thesilicone oil comprises about 30 mol % diphenyl siloxane and about 70 mol% dimethyl siloxane.
 9. The IOL of claim 1, wherein the silicone oilcomprises from about 5% to about 10% long chain polysiloxane moleculesby weight.
 10. The IOL of claim 1, wherein the silicone oil has aviscosity between about 400 cSt at 25° C. to about 800 cSt at 25° C. 11.The IOL of claim 1, wherein the silicone oil has a refractive indexbetween 1.49-1.53.
 12. The IOL of claim 1, wherein the silicone oilcomprises less than 0.1% octamethylcyclotetrasiloxane,decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxone.
 13. TheIOL of claim 1, wherein the silicone oil has a mean molecular weightfrom about 1,000 to about 3,000 Daltons.